American Medical Association Family Medical Guide - American Medical Association [812]
prophylactic Preventing disease.
prostaglandins Substances similar to hormones; secreted in many tissues. Prostaglandins produce a variety of effects throughout the body, such as pain and inflammation in damaged tissue.
prostate-specific antigen A protein produced only by the prostate gland. High levels of the protein in blood can indicate a problem with the prostate gland such as enlargement or cancer.
prosthesis A man-made replacement (such as an artificial arm or leg, dental bridge, breast implant, or glass eye) for a diseased or missing body part.
proteins Complex substances composed of amino acids. Proteins are the basis of all living matter.
PSA See prostate-specific antigen.
PSA test Prostate-specific antigen test. A test to measure the levels of prostate-specific antigen in the blood; an increased level of PSA may indicate prostate enlargement or prostate cancer.
psychosis A severe mental disorder in which a person loses touch with reality.
pus A creamy yellow or pale green liquid composed of dead white blood cells, bacteria, and other substances that forms at the site of an infection.
R
radiation therapy Treatment with a stream of particles or electromagnetic waves emitted by the atoms and molecules of a radioactive substance; used to destroy abnormal growths such as cancer.
radiation therapy, internal See brachytherapy.
red blood cells Doughnut-shaped blood cells that carry oxygen to and remove wastes from organs and tissues.
rejection An attack by the immune system on grafted tissue or a transplanted organ; may be prevented by treatment with drugs that suppress the immune system.
remission A temporary disappearance of symptoms of a chronic disease (such as cancer or multiple sclerosis). If remission lasts more than 5 years, the disease is usually considered cured.
respirator See ventilator.
retina The light-sensitive membrane at the back of the eye on which light rays focus.
ribonucleic acid See RNA.
RNA Ribonucleic acid. A type of genetic material that carries out the instructions of a cell’s DNA.
S
SAD See seasonal affective disorder.
salt-sensitive Describes a person whose blood pressure goes up or down in relation to the amount of sodium in his or her diet.
sarcoma A rare, difficult-to-treat cancerous
tumor of connective tissue, blood vessels, or fibrous tissue surrounding and supporting organs.
saturated fat A type of fat (found in meat, dairy products, and coconut and palm oils) that is converted to harmful LDL cholesterol and is thought to increase the risk of heart disease and heart attacks.
seasonal affective disorder Also called SAD. A form of depression that tends to occur during the fall and winter, when there are fewer hours of daylight.
secondary hypertension High blood pressure that has a known underlying cause.
seizure Excessive electrical activity in the brain that causes temporary loss of consciousness or memory, or uncontrolled movements.
sensitization The initial exposure to an allergen, which causes a reaction by the immune system. On subsequent exposure to the allergen, the reaction becomes stronger.
sensory Of or relating to the senses; transmitting impulses from the senses to nerve centers in the brain.
septicemia Also called blood poisoning. A life-threatening blood infection in which bacteria enter the bloodstream, multiply rapidly, and release toxins.
serotonin A neurotransmitter that conveys messages between brain cells; involved in regulating mood.
sex chromosomes The X and Y chromosomes, which determine sex. Females have two X chromosomes; males have one X chromosome and one Y chromosome.
sexually transmitted diseases Also called STDs. Infections transmitted through sexual activity.
sleep apnea See apnea, sleep.
sodium An essential mineral that helps the body maintain water balance and blood pressure.